The reasoning behind why the Toronto Blue Jays trade Spencer Horwitz announced

From the infielder's perspective, his path to consistent playing time on the field was blocked by All-Star first baseman Vladimir Guerrero Jr. As a natural first baseman, the Jays had Horwitz take reps at second base but his fielding ability lacked behind most of the other internal options and he spent a good chunk of the stretch in the DH spot instead. There wasn't an outcome where Horwitz could replace Guerrero barring the slugger moving to third base. -Chung

While it would have been desirable for Toronto to part ways with the least promising talents in their depth charts, the nature of the trade market requires paying a higher price. In that sense, sending someone of Horwitz's calibre to bring players who can effectively fill in the missing gaps. -Chung